Correct option is D
The ideal op-amp has these characteristics:
Input impedance (differential or common-mode) = infinity
Output impedance (open loop) =0
Voltage gain = infinity
Common-mode voltage gain =0
Output can change instantaneously (infinite slew rate)
The purpose of bias current is to achieve the ideal behavior in op-amp which is high CMRR, high differential gain, and high input impedance
